Surface plasmon resonance device

Abstract

A surface plasmon resonance device of the present invention includes a transparent medium layer and a conductive layer, a periodic structure being present at the interface therebetween. Assuming that the wavelength of visible light incident on the conductive layer through the transparent medium layer is λ (nm), the periodicity of the periodic structure is (λ / 633)×100 nm to (λ / 633)×500 nm, and the amplitude of the periodic structure is (λ / 633)×5 nm to (λ / 633)×20 nm. For example, when λ=633 nm, the periodicity of the periodic structure is 100 nm to 500 nm, and the amplitude is 5 nm to 20 nm.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a surface plasmon resonance device, and particularly to a surface plasmon resonance device suitably used for measuring the dielectric constants of various samples. [0003] 2. Description of the Related Art [0004] A conventional known method for measuring the dielectric constant of a surface of a sample is a surface plasmon resonance method (for example, Japanese Unexamined Patent Application Publication No. 11-271215). Among modes of plasmons referring to collective resonance of free electrons present in a conductive material such as a metal or the like, the conventional method uses a surface plasmon mode in which plasmons are localized at a surface of the conductive material. The principle of measurement is as follows: Surface plasmons are coupled with an electromagnetic wave in a dielectric material at an interface between the dielectric material and a conductive material such as a ...

AI Technical Summary

Benefits of technology

[0018] In the present invention, even when a dielectric sample has a higher dielectric constant than that of the transparent medium layer, an electromagnetic wave propagating in the transparent medium layer is strongly coupled with surface plasmons at the interface between the conductive layer and the dielectric sample, thereby permitting measurement of the higher dielectric constant of the dielectric sample than that of the transparent medium layer.

Problems solved by technology

However, when an interface between a dielectric material and a conductive material such as a metal or the like is planar, an electromagnetic wave propagating in the dielectric material cannot be coupled with the plasmons in the conductive material.

However, for a sample having a higher dielectric constant than that of a transparent medium, the dielectric constant cannot be measured by the above-mentioned method.

Thus, an electromagnetic wave propagating in the transparent medium cannot be coupled with surface plasmons at the metal-dielectric sample interface.

Consequently, there is the problem that the dielectric constant of the sample cannot be measured with light incident on the transparent medium layer.

Images